Swimming is a good exercise but it is also a skilled exercise that the swimmer pushes the water backward to let the body move forward. In order to effectively push a large amount of water backward to produce a large force to push the swimmer's body, the swimmer has to adjust his/her wrists and ankles to let the hands and feet orient perpendicularly to the forward direction so as to push a larger amount of water. However, the areas of the hands and the feet are limited. Fins are therefore used to increase the area to push the water. Once the fins are worn on the feet, they will affect the actions of the swimmer in the water even when the swimmer does not need the resistant force. The swimmer cannot walk as those who have no fins on their feet so that the swimmer has to wear on the fins when he/she wants to swim, and remove the fins when he/she is on the shore. Furthermore, The fins occupy a large space and are convenient for being carried with the swimmer.
The present invention intends to provide a swimming auxiliary device which is attached to the calf or the forearm and has a pivotable web member which is expanded relative the calf or the forearm when pushing the water so as to effectively increase the areas to push the water backward. The present invention provides a convenient tool to assist the swimmer to swim more efficiently.